IBM 88743BU - System x3950 E User Manual page 140

Notes:
As previously mentioned, hot-add and hot-swap are mutually exclusive.
You can enable only one of these features.
If you plan to enable hot-add memory and you have a x3850 M2 or
x3950 M2 system that comes standard with two memory cards, move
memory card 2 to slot 3 to be able to hot-add memory cards in slots
2 and 4.
After you add a memory card that has two DIMMs, you cannot add more
memory to that same memory card without powering off the server.
Enabling hot-add reserves a portion of the memory map for the memory
that can be hot-added in the future. If you do not plan to use hot-add, we
recommend that you do not enable this feature in BIOS.
Memory Array Setting (memory mode)
Available memory modes and the features they enable are listed in Table 3-9.
Table 3-9 Memory configuration modes in BIOS
Mode
HPMA (high performance memory array)
FAMM (full array memory mirroring)
HAM (hot-add memory)
The memory configuration mode you select depends on the memory features
you want to use. Select one of the following modes:
HPMA if you are
default or standard setting.
FAMM enables memory mirroring and hot-swap.
HAM enables hot-add in the future.
Note: The memory setting must be the same for all nodes in a multinode
complex before merging the scalable partition. This requires a KVM
connection to each node before the scalable partition is created.
Unlike with the x3850, the x3850 M2 and x3950 M2 support Memory ProteXion
with the HPMA setting, providing maximum performance, and they continue to
provide the reliability of Redundant Bit Steering (RBS).
122
Planning, Installing, and Managing the IBM System x3950 M2
Memory Memory
ProteXion Mirroring
Yes Disabled
Yes Yes
Yes Disabled
not
using mirroring, hot-swap, or hot-add. This is now the
Hot-swap Hot-add
memory memory
Disabled Disabled
Yes Disabled
Disabled Yes